Wirz, Dick: - Dick Wirz is a Master Electrician and Master HVACR Mechanic in the states of Virginia and Maryland, as well as Washington, DC. A NATE-certified technician with more than four decades of professional experience, Dick owned and operated a successful commercial refrigeration company for 25 years and taught HVACR at a community college for another 15 years. Now semi-retired, Dick produces HVACR instructor aids in the form of animated slideshows under the name of Refrigeration Training Services at www.hvacteaching.com.